A typical packet based communication system discards a packet if it contains bit errors. In order to find the errors in the packet, in general, receiver needs to execute the frame validity check procedure based on the FCS (frame check sequence) which is available at the end of the packet. In that case, the receiver is not able to tell whether or not the packet is error-free until the entire packet is received and processed. Therefore, in high packet error rate environments, the receiver ends up wasting power to process entire packets although a majority of them are going to be discarded.
Meanwhile, typical communication systems employ the HCS (header check sequence) to identify an invalid packet header because the packet header contains demodulation parameters which are essential to decode a received packet correctly. However, for some communication systems such as IEEE P802.15.6 (personal area network physical layer standard (such as IEEE P802.15-09-0329-00-0006, Wireless Personal Area Networks, MedWiN Physical Layer Proposal)), the HCS is not very reliable to catch all header errors. For example, the HCS in IEEE P802.15.6 employs only a two-bit HCS, which implies that at least 25% of invalid packet headers are regarded as valid headers if they pass the HCS by coincidence. The misdetection of an invalid packet header (that is, when an invalid packet header passes the HCS check) causes significant processing power waste at the receiver because errors in the packet header result in incorrect packet decoding.
What is needed is a method for codeword failure detection technique enabling early termination of packet processing at receivers where packet errors (a packet is made up of many codewords) or header errors are detected before the end of the packet without checking FCS or HCS. System level power saving can be achieved by discarding the received packet immediately when the proposed codeword failure detector asserts a codeword failure.